From ac20ab031ca08a031b2dea321ba50ee4c86b18c4 Mon Sep 17 00:00:00 2001
From: Thomas Faber <thomas.faber@reactos.org>
Date: Wed, 6 Mar 2019 09:57:23 +0100
Subject: [PATCH] [USBPORT] Correctly handle alternate settings returned from
 USBPORT_ParseConfigurationDescriptor.

The last parameter of USBPORT_ParseConfigurationDescriptor is a pointer
to a boolean indicating whether any alternate interface settings were
found for the specified interface.
Interpreting it as an alternate setting value, as we did before,
would always override the alternate setting to '1' (if any alternate
descriptors were present), therefore selecting the wrong interface
setting, and possibly causing a buffer overflow on the InterfaceList's
Pipes array.

Found by Special Pool.
---
 drivers/usb/usbport/device.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/usbport/device.c b/drivers/usb/usbport/device.c
index 5662a6141af..86765719856 100644
--- a/drivers/usb/usbport/device.c
+++ b/drivers/usb/usbport/device.c
@@ -186,7 +186,7 @@ NTAPI
 USBPORT_ParseConfigurationDescriptor(IN PUSB_CONFIGURATION_DESCRIPTOR ConfigDescriptor,
                                      IN UCHAR InterfaceNumber,
                                      IN UCHAR Alternate,
-                                     OUT PUCHAR OutAlternate)
+                                     OUT PBOOLEAN HasAlternates)
 {
     PUSB_CONFIGURATION_DESCRIPTOR TmpDescriptor;
     PUSB_INTERFACE_DESCRIPTOR iDescriptor;
@@ -197,8 +197,8 @@ USBPORT_ParseConfigurationDescriptor(IN PUSB_CONFIGURATION_DESCRIPTOR ConfigDesc
 
     DPRINT("USBPORT_ParseConfigurationDescriptor ... \n");
 
-    if (OutAlternate)
-        *OutAlternate = 0;
+    if (HasAlternates)
+        *HasAlternates = FALSE;
 
     for (TmpDescriptor = (PUSB_CONFIGURATION_DESCRIPTOR)((ULONG_PTR)ConfigDescriptor + ConfigDescriptor->bLength);
          TmpDescriptor->bDescriptorType != USB_INTERFACE_DESCRIPTOR_TYPE && TmpDescriptor->bLength > 0;
@@ -235,8 +235,8 @@ USBPORT_ParseConfigurationDescriptor(IN PUSB_CONFIGURATION_DESCRIPTOR ConfigDesc
         ++ix;
     }
 
-    if ((ix > 1) && OutAlternate)
-        *OutAlternate = 1;
+    if ((ix > 1) && HasAlternates)
+        *HasAlternates = TRUE;
 
     return OutDescriptor;
 }
@@ -256,6 +256,7 @@ USBPORT_OpenInterface(IN PURB Urb,
     PUSBPORT_PIPE_HANDLE PipeHandle;
     PUSB_ENDPOINT_DESCRIPTOR Descriptor;
     PUSBD_PIPE_INFORMATION PipeInfo;
+    BOOLEAN HasAlternates;
     ULONG NumEndpoints;
     SIZE_T Length;
     SIZE_T HandleLength;
@@ -271,14 +272,14 @@ USBPORT_OpenInterface(IN PURB Urb,
     InterfaceDescriptor = USBPORT_ParseConfigurationDescriptor(ConfigHandle->ConfigurationDescriptor,
                                                                InterfaceInfo->InterfaceNumber,
                                                                InterfaceInfo->AlternateSetting,
-                                                               &InterfaceInfo->AlternateSetting);
+                                                               &HasAlternates);
 
     NumEndpoints = InterfaceDescriptor->bNumEndpoints;
 
     Length = FIELD_OFFSET(USBD_INTERFACE_INFORMATION, Pipes) +
              NumEndpoints * sizeof(USBD_PIPE_INFORMATION);
 
-    if (InterfaceInfo->AlternateSetting && IsSetInterface)
+    if (HasAlternates && IsSetInterface)
     {
         DPRINT1("USBPORT_OpenInterface: InterfaceInfo->AlternateSetting && IsSetInterface !\n");
     }
@@ -491,7 +492,7 @@ USBPORT_InitInterfaceInfo(IN PUSBD_INTERFACE_INFORMATION InterfaceInfo,
     Descriptor = USBPORT_ParseConfigurationDescriptor(ConfigHandle->ConfigurationDescriptor,
                                                       InterfaceInfo->InterfaceNumber,
                                                       InterfaceInfo->AlternateSetting,
-                                                      &InterfaceInfo->AlternateSetting);
+                                                      NULL);
 
     Length = sizeof(USBD_INTERFACE_INFORMATION) +
              sizeof(USBD_PIPE_INFORMATION);